South Korea's Seongnam city government is moving the Bokjeong-dong Seongnam Water Quality Restoration Center about one kilometer to the Tancheon riverside in Taepyeong-dong and burying it underground, freeing roughly 270,000 square meters of surface land for 3,000 youth housing units, a startup support hub, and advanced IT and bio industry facilities, according to a Chosunbiz report published 31 August 2026 (Chosunbiz).
Key takeaways
- Seongnam's 460,000-ton-per-day Seongnam Water Quality Restoration Center, completed in 1994, will be relocated about 1 km to a new underground riverside site (Chosunbiz).
- The existing 270,000 m² site is earmarked for 3,000 public housing units for youth and newlyweds, a startup support facility, and an IT and bio industry complex (Chosunbiz).
- The project passed South Korea's Ministry of Economy and Finance private investment review in July 2024, with the Seongnam Ecopia consortium, including Samsung E&A, named preferred bidder at the end of that year (Chosunbiz).
- Seongnam targets groundbreaking at the end of 2026 and completion by the end of 2030 (Chosunbiz).
- Seoul is studying a parallel move of the Tancheon Water Reclamation Center in Ilwon-dong, Gangnam, into youth housing and an advanced industry hub including physical AI (Chosunbiz).
What happened in Seongnam
The Seongnam Water Quality Restoration Center, which entered service in 1994, treats 460,000 tons of sewage a day and has faced ongoing facility aging and odor complaints, according to the Chosunbiz report (Chosunbiz). The Seongnam city government told residents the old facilities cost more than 5 billion won a year to maintain, the report said (Chosunbiz). The transfer plan pairs the new underground plant with parks and sports facilities on the surface at the original site.
The Seongnam city government and Korea Land & Housing Corporation (LH) signed a business agreement in 2020 to develop the vacated 270,000 m² site into 3,000 public housing units for youth and newlyweds and a startup support facility (Chosunbiz). The plan has since been widened to include a complex hub supporting advanced IT, bio industries, and youth startups.
Procurement timeline
| Milestone | Date / Status | Source |
|---|---|---|
| LH business agreement signed | 2020 | Chosunbiz |
| Ministry of Economy and Finance private investment review passed | July 2024 | Chosunbiz |
| Seongnam Ecopia consortium (incl. Samsung E&A) named preferred bidder | End of 2024 | Chosunbiz |
| Implementation agreement and implementation plan approval | Pending; construction targeted for end of 2026 | Chosunbiz |
| Scheduled completion | End of 2030 | Chosunbiz |
Comparable projects in the same programme
Seoul is running a feasibility review for a private investment project to modernize the Tancheon Water Reclamation Center in Ilwon-dong, Gangnam District, considering youth housing and advanced industry facilities such as physical AI on the vacated land, the Chosunbiz report said (Chosunbiz). Daejeon is consolidating the Wanchon-dong sewage treatment plant and the Ojeong-dong excrement treatment plant in Daedeok District into a 140,000 m² underground site in Geumgo-dong, Yuseong District, with a 650,000 m³/day capacity and an ecological park above ground; construction began in 2023 and completion is targeted for 2028, and the vacated Wanchon-dong site will be turned into an advanced biomedical innovation district (Chosunbiz). Anyang's Saemul Park, built by burying the Bakdal Sewage Treatment Plant underground, covers about 180,000 m² and continues to treat 250,000 tons of sewage a day beneath sports facilities and green space (Chosunbiz).
Specification read
The Seongnam plant operates at 460,000 tons per day, or roughly 460,000 m³/day, equivalent to about 2.3 million population equivalent at a typical 200 litres per capita per day design load (general industry range, not from the sources). The reported Daejeon combined plant adds another 650,000 m³/day of underground capacity on top of that, putting the two new buried assets alone close to 1.1 million m³/day once Daejeon completes in 2028. A class of project this size normally runs screening and grit removal, primary clarification, a biological nutrient removal stage such as A2O or MBR, tertiary filtration, and disinfection before reuse or discharge; underground siting is a civil-engineering decision and does not change the treatment train itself. The procurement signal here is the underground relocation and rebuild of an existing asset, not a new greenfield influent stream, so a bidder for the buried tankage, odour control, and process mechanical packages is looking at the workhorse stages of Integrated Sewage Treatment equipment, with Underground Package Sewage Treatment Plant (WSZ Series) as the smaller-site counterpart for utilities that want buried process equipment without a full civil relocation. If your plant is a 100,000–500,000 m³/day municipal works with aging civil structures, rising odour complaints, and a real-estate pressure to free surface land, this Korean programme is the reference case for what an underground-relocation tender package looks like and where the Air Dust Treatment envelope on the buried headworks and grit tanks gets priced. For utilities weighing the trade-off, the Anaerobic Digester for Domestic Sewage: 2026 Engineering Guide and the DAF vs Clarifier for San Diego Food & Bev Wastewater: 2026 Selection Guide cover the side-stream and pretreatment decisions that sit alongside a buried main train.
FAQ
How big is the Seongnam plant being moved, in m³/day?
The Seongnam Water Quality Restoration Center treats 460,000 tons per day, which converts to 460,000 m³/day assuming a sewage density of about 1 t/m³. At a typical 200 L per capita per day design load that is roughly 2.3 million population equivalent (general industry range, not from the sources). The full capacity figure is reported by Chosunbiz.
What is the procurement route and the likely lead time?
The Seongnam project is being run as a private investment scheme that cleared the Ministry of Economy and Finance review in July 2024, with the Seongnam Ecopia consortium, including Samsung E&A, named preferred bidder at the end of 2024 (Chosunbiz). Seongnam targets groundbreaking at the end of 2026 and completion at the end of 2030, implying a roughly four-year build once the implementation agreement is signed.
How much will the vacated land be worth to the city?
The report puts the operating-cost saving of the existing plant at more than 5 billion won a year and the freed-up site at about 270,000 m², earmarked for 3,000 youth and newlywed public housing units plus an IT and bio industry hub (Chosunbiz). No land sale price is reported.
What can a utility learn from this for its own site?
The Korean cases pair an underground rebuild of the treatment train with a defined upper-site use, which is the model Anyang's Saemul Park already operates at 250,000 t/day beneath sports and park space (Chosunbiz). For a plant under odour or land-pressure stress, the lesson is to scope the buried civil package and the surface master plan together rather than as separate tenders.
